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(2) Victron Quattro 5K 24V shut off with “Overload” & “Low battery” Fault when 300A Alternator is turned on.

Hi everyone, I am with an OEM Motorhome manufacture. We have recently made the switch to Victron but have experienced an issue that has me boggled.


We use (2) 24V 5K Quattro inverters, wired standalone of each other, but to the same bank of batteries. They are tied to (14) LiOn Energy 1300W batteries. The system works fantastic, and just as advertised UNITL, you start the main motorhome engine and the (2) 24V 150A alternators go to work. As long as the inverters are just “inverting”, everything still works. As soon as an AC Power source is applied, the inverters make the attempt to switch to charge, but then immediately shut down with an “Overload” and “Low battery” fault lights, they will not come back on until either AC power is no longer supplied, or you shut the alternators off. I assume that this has something to did with the amount of current being thrown at the batteries while the inverters are attempting to charge at the same time. Maybe a DC Ripple effect causing them to shut down? Anyone deal with this, or have any suggestions?


Thanks!

MultiPlus Quattro Inverter Charger
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mt-geek avatar image mt-geek commented ·

What is the voltage the alternator put out compared to the float setting in the Quattro

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ggarrisongcsd avatar image ggarrisongcsd mt-geek commented ·

The alternator will put out 28.8, the float voltage of the Quattro is set to 27.8.

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mrseas avatar image mrseas commented ·

Are you using the "alternators" to supply AC or DC voltage to the Quattros?

Have you mad any changes to the "default" settings in the Quattros?

Each Quattro running a separate side of the "breaker" panel?


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ggarrisongcsd avatar image ggarrisongcsd mrseas commented ·

Alternators supply DC Voltage direct to the batteries, just the same bus that the Quattro are connected. Yes, each inverter is independent to the breaker panel with isolated neutrals. I changed the charge profile on both inverters to LiFePoE, and adjusted the float to 27.8.

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ggarrisongcsd avatar image ggarrisongcsd commented ·

Wanted to add an update here. I changed the charge curve from fixed to adaptive to allow the inverters to continue to charge when the battery voltage does in fact go above 28V. When it was set to fixed the voltage didn’t fit into their curve and that is what was kicking them off. After making this change they seem to work perfectly fine for now, have a little over 3 hours of testing to verify.

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janieronen answered ·

Hi

As Lion batteries have suggested, charge 45A =315A for 7S2P(14) batteries but quite low max voltage 27,8V. What are your charge voltage settings on Quattros, and have you measured how high bus voltage is when an overload occurs? Two quattros can supply 240A + your 300A so that in total exceeds suggested charge amps.

Do you have BMS in the system or a shunt to inform total amperage to Quattros?
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marekp avatar image marekp commented ·

"As Lion batteries have suggested, charge 45A =315A for 7S2P(14) batteries but quite low max voltage 27,8V."

Can you explain how you come up with 315A for 7s2p pack?

I think for this configuration, and 45A max for a cell, the max current for this pack is 90A.

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ggarrisongcsd avatar image ggarrisongcsd commented ·

Hi! Thanks for the response, there is currently nothing installed for the Quattro to know the total amperage.

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